The usual objective of any sanding operation is to remove unwanted material from the surface being sanded and to prepare that surface for subsequent coating operations. Typically, these two objectives are diametrically opposed. Removing unwanted material from the surface in a reasonable amount of time requires the use of a coarse abrasive while preparing the surface for subsequent coating operations requires the use of a fine abrasive. Thus, the operator must sand the surface multiple times with a succession of increasingly finer grit sandpaper to achieve both objectives. The coarse sandpaper removes unwanted material quickly. However, a progression of increasingly finer sandpaper is often needed to remove the unacceptably deep scratches left in the surface by the coarse sandpaper. This entire sanding process is viewed by many as laborious, time consuming, and generally distasteful. Sandpaper manufacturers recognize this dilemma and have offered many products in an attempt to solve the problem.
Conventional sandpaper is usually produced by combining a relatively thin inflexible backing (paper, film etc.), a relatively stiff make adhesive (urea formaldehyde resin, hide glue, phenolic resin, etc.), abrasive mineral, and a relatively inflexible size resin (urea formaldehyde resin, hide glue, phenolic resin, etc.). Conventional sandpaper is thus fairly stiff and inflexible, but has an aggressive cut.
Conventional sanding sponges are relatively flexible and produce a fine scratch pattern, but lack significant cut. Flexible sanding cloths combine thick, conformable screen-like backings to make a product that has both the comfort and ease of use of conventional foam sanding sponges and the aggressive cut of conventional sandpaper. The open spaces adjacent each of the resilient bodies of the sanding cloth mesh serve as reservoirs to collect the dust generated during the sanding process. This effectively removes the sanding dust from the abrasive surface, resulting in less abrasive surface clogging and improved stock removal.
Surprisingly, the results of scratch finish testing of the sanding cloth and a conventional sanding sponge demonstrate that a significantly finer scratch pattern is left in the sanded surface by a sanding cloth than a conventional sanding sponge of comparable abrasive grit. These results can be explained by the checkerboard arrangement of small abrasive coated resilient bodies. Each of the abrasive coated resilient bodies is essentially a small sanding sponge that collectively provide unique properties. The checkerboard arrangement of the abrasive coated resilient bodies, however, also contributes to the fine finish left in the sanded surface. Because each abrasive coated resilient body is connected to an adjacent abrasive coated resilient body with an inherently flexible joint, each abrasive coated resilient body is free to follow a slightly different path across the sanded surface. This results in multiple overlapping sanding paths with a fine scratch finish. Many of the individual sanding paths will overlap each other during the surface finishing process yielding an unexpectedly fine sanding scratch pattern.
As described above, the sanding cloth material can provide desirable cut (i.e. stock removal) with less scratching (i.e. smoother finish). Certain applications outside traditional wood or metal sanding, however, require very low scratch or less harsh minerals. The fine scratch pattern and the conformable backing of the sanding cloth can be combined with “soft mineral” to achieve these desired results. Examples of low scratch applications include cleaning and scouring, polishing and buffing, cosmetics, and medical and dental applications. Furthermore, encapsulated materials may be coated as particles on the sanding cloth material. The material contained within the encapsulant would be released with product use. This would allow delivery of many types of material to the work surface, such as polishes, cleaners, and medical compounds.